This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. There is an unmet need for effective, efficient and economical methods for conducting clinical trials to prevent Alzheimer s disease. Traditional in-person visits to a clinic are time consuming and costly and may exclude certain individuals from participation, such as those who are older, or are less mobile or who have significant medical illnesses. These may be the very people who are at greatest risk for cognitive decline, as well as those without financial resources for transportation to a study site. Prevention trials also require long observation periods and these same issues of health, resources, and transportation may cause significant drop out. These obstacles increase expense of clinical trials as they require large sample sizes, costly clinical staff and long observation periods. Thus, home-based assessments may lead to more representative recruitment of those most at risk for decline, better retention and reduced study costs.